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/* $Id$ */
/** @file endian_check.cpp
* This pretty simple file checks if the system is LITTLE_ENDIAN or BIG_ENDIAN
* it does that by putting a 1 and a 0 in an array, and read it out as one
* number. If it is 1, it is LITTLE_ENDIAN, if it is 256, it is BIG_ENDIAN
*
* After that it outputs the contents of an include files (endian.h)
* that says or TTD_LITTLE_ENDIAN, or TTD_BIG_ENDIAN. Makefile takes
* care of the real writing to the file. */
#include <stdio.h>
#include <string.h>
/** Supported endian types */
enum Endian {
ENDIAN_LITTLE, ///< little endian
ENDIAN_BIG ///< big endian
};
/**
* Shortcut to printf("#define TTD_*_ENDIAN 0/1")
* @param endian endian type to define
*/
static inline void printf_endian(Endian endian)
{
printf("#define TTD_ENDIAN %s\n", endian == ENDIAN_LITTLE ? "TTD_LITTLE_ENDIAN" : "TTD_BIG_ENDIAN");
}
/**
* Main call of the endian_check program
* @param argc argument count
* @param argv arguments themselves
* @return exit code
*/
int main (int argc, char *argv[])
{
unsigned char endian_test[2] = { 1, 0 };
int force_BE = 0, force_LE = 0, force_PREPROCESSOR = 0;
if (argc > 1 && strcmp(argv[1], "BE") == 0) force_BE = 1;
if (argc > 1 && strcmp(argv[1], "LE") == 0) force_LE = 1;
if (argc > 1 && strcmp(argv[1], "PREPROCESSOR") == 0) force_PREPROCESSOR = 1;
printf("#ifndef ENDIAN_H\n#define ENDIAN_H\n");
if (force_LE == 1) {
printf_endian(ENDIAN_LITTLE);
} else if (force_BE == 1) {
printf_endian(ENDIAN_BIG);
} else if (force_PREPROCESSOR == 1) {
/* Support for universal binaries on OSX
* Universal binaries supports both PPC and x86
* If a compiler for OSX gets this setting, it will always pick the correct endian and no test is needed
*/
printf("#ifdef __BIG_ENDIAN__\n");
printf_endian(ENDIAN_BIG);
printf("#else\n");
printf_endian(ENDIAN_LITTLE);
printf("#endif\n");
} else if (*(short*)endian_test == 1 ) {
printf_endian(ENDIAN_LITTLE);
} else {
printf_endian(ENDIAN_BIG);
}
printf("#endif\n");
return 0;
}
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